Honda Accord 2004 engine rotates but won't start
 

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Hi everyone,

Here's the situation:

A few days ago I noticed my check engine light came on after driving on the highway. After drum practice I was able to start the car with no issues but the CEL was still on. I was able to drive the car home. The next day the car would not start. The engine rotates but it will not start. I tried to jump the car and that did not work. Checked the voltage output on the battery and it came out fine. I did notice that when I turn the key to the ON position the green key light flashes non-stop. Any ideas as to what could be the problem battery, ignition, fuel, etc.? Any help would be greatly appreciated, thanks!


2004 Honda Accord EX
4 cycl. MT

Re: Honda Accord 2004 engine rotates but won't start
 

Could be the Crankshaft Position Sensor is bad. Engine turning with no spark is a classic symptom of this and - unfortunately, many other issues. The technician at any garage should be able to hook up to the computer and see if this is the case. It was on my vehicle. The CPS functions as an emergency fuel cut off when it senses that the crankshaft is no longer spinning (i.e., when a collision has occured). This is why a bad sensor will cut off fuel from the engine causing crank but no ignition.

Re: Honda Accord 2004 engine rotates but won't start
 

Thanks for the reply. What car do you own?

Do faulty CKPs activate the immobilizer? I may check for a faulty CKP once I can find a specific tutorial online.

Re: Honda Accord 2004 engine rotates but won't start
 

I would look into the immobilizer (green key flashing) I think that's the culprit before looking any lower down the chain. Try a different key maybe? Look into potential recalls (I don't have this gen accord so I can't speak on that but my 6th gen has some ignition issues. try jiggling the key too.

Re: Honda Accord 2004 engine rotates but won't start
 

I've tried the two keys I have, the master and valet keys. I've been able to enter the emergency brake code to bypass the immobilizer but the car still does not start. This is the part that's puzzling me. Is there more than one issue with the no start (immobilizer and ignition/fuel system)?

Dealership quoted 3+ hrs to diagnose the issue. They said there is no communication with immobilizer and pcm to shut off the immobilizer. I'm not too sure what to make of this.

Re: Honda Accord 2004 engine rotates but won't start
 

Update:

I've traced the problem down to the ECM not getting any power. Looks like the Main Relay isn't getting a ground to complete the circuit to send power to the ECM. Is anyone up for helping find the root cause of this?

Re: Honda Accord 2004 engine rotates but won't start
 

Is the fuel pump running for ~2 seconds when you turn the key to on?

Re: Honda Accord 2004 engine rotates but won't start
 

Thanks for all suggestions. I was able to fix the problem. It turns out to be a faulty ECM. While doing electrical testing at the ECM I decided to pull it out and water was dripping out. Opened it up and circuits looked fried. Replaced the ECM with a used one from a seller on EBAY, towed the car over to the dealership and they repogrammed the ECM/immobilizer. Car started up.

Some signs that may point to a faulty ECU:

Immobilizer faulty, FI MAIN relay not working, MIL/CEL does not come on at all when key is in ON position. At the ECU, proper connectors not getting the right voltage/ground. Specifically ECU not grounding hence setting off other chains of malfunctions from relays up to immobilizer and start up.

Re: Honda Accord 2004 engine rotates but won't start
 

Great job!

Re: Honda Accord 2004 engine rotates but won't start
 

check your evaporator drain pipe, might be cloggged or pinched, if not it will happen again.